The present invention generally relates to fuel-fired liquid heating apparatus and, in a representatively illustrated embodiment thereof, more particularly provides a fuel-fired water heater having disposed in a combustion chamber portion thereof specially designed heat concentration apparatus operative to reduce standby heat losses and thereby improve overall efficiency of the water heater by concentrating the heat of a standing pilot flame on an underside portion of the bottom wall of the storage tank portion of the water heater. According to a further aspect of the invention, the overall efficiency of the water heater may also be increased by the use and a unique control of a dual input standing pilot burner.
In previously proposed fuel-fired water heater designs, the water heater has, within its combustion chamber, a pilot burner operative to maintain a standing pilot flame during “standby” periods of the water heater in which its main burner is not being fired. The heat from the standing pilot flame may simply escape through the vertical flue of the water heater without adding appreciable heat to water stored in the tank portion of the water which overlies the combustion chamber, or sometimes overheat the tank water during standby periods. From an operational standpoint, neither of these conditions is ideal.
It would accordingly be desirable to provide an improved water heater pilot burner system that addresses these conditions. It is to this goal that the present invention is primarily directed.